adding to a ddmmyyyy date

[ginajohnst]

Hi All.

I'm having a problem adding days to a date.

My date is in the string format dd/mm/yyyy eg. 23/08/2007 in my
form field.

I can't work out how to add 50 days to that date and then write it to
another form field.

Any help would be appreciated.

[David Mark]

On Aug 8, 3:16 am, ginajohnst <[e-mail]:

Hi All.

I'm having a problem adding days to a date.

My date is in the string format dd/mm/yyyy eg. 23/08/2007 in my
form field.

I can't work out how to add 50 days to that date and then write it to
another form field.

Any help would be appreciated.

Which part can't you figure out? See the FAQ for date manipulation.
To change a form element's value, set its value property.

[Dr J R Stockton]

In comp.lang.javascript message <46**************@PointedEars.de>, Wed,
8 Aug 2007 10:42:09, Thomas 'PointedEars' Lahn <Po*********@web.de>
posted:

>Quickhack:

but not well tested. It gives
23/02/2007 + 50 -12/04/2007
23/08/2007 + 50 -12/10/2007

But February is shorter than August, and should give days 3 more.

var
a = formField.value.split("/"),
d = new Date(
parseInt(a[2], 10), parseInt(a[1], 10), parseInt(a[0], 10) + 50);

d = new Date(a[2], a[1]-1, a[0]+50) // suffices

One can replace, in this context, parseInt by unary +; and that will in
context be effectively implicit.

anotherFormField.value =
String(d.getDate() * 1e6 + d.getMonth() * 1e4 + d.getFullYear())
.replace(/(\d\d)(\d\d)(\d{4})/, "$1/$2/$3");

Do you find that better than, with suitable LZ,

anotherFormField.value =
LZ(d.getDate()) + '/' + LZ(d.getMonth()+1) + '/' + d.getFullYear()

// ??

It's a good idea to read the newsgroup c.l.j and its FAQ. See below.

--
(c) John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v6.05 IE 6
news:comp.lang.javascript FAQ <URL:http://www.jibbering.com/faq/index.html>.
<URL:http://www.merlyn.demon.co.uk/js-index.htmjscr maths, dates, sources.
<URL:http://www.merlyn.demon.co.uk/TP/BP/Delphi/jscr/&c, FAQ items, links.

[Dr J R Stockton]

In comp.lang.javascript message <f9*********@drn.newsguy.com>, Wed, 8
Aug 2007 05:48:47, Lee <RE**************@cox.netposted:

>My date is in the string format dd/mm/yyyy eg. 23/08/2007 in my

>Once you understand it completely, you should be able to come up
with a much simpler solution that actually works.

http://docs.sun.com/source/816-6408-10/date.htm

/* There must be a nicer-looking version of that page, with a margin */
/* Note its error in a line starting like <tt>milliseconds</tt*/
/* They seem to ignore that UT != UTC */

Which parts of that page d0 you believe to deal with the reading and
writing of non-FFF numeric date strings??

--
(c) John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v6.05 IE 6.
Web <URL:http://www.merlyn.demon.co.uk/- w. FAQish topics, links, acronyms
PAS EXE etc : <URL:http://www.merlyn.demon.co.uk/programs/- see 00index.htm
Dates - miscdate.htm moredate.htm js-dates.htm pas-time.htm critdate.htm etc.

[Thomas 'PointedEars' Lahn]

Dr J R Stockton wrote:

[...] Thomas 'PointedEars' Lahn [...] posted:

>Quickhack:

but not well tested.

Hence *quick**hack*.

It gives
23/02/2007 + 50 -12/04/2007
23/08/2007 + 50 -12/10/2007

But February is shorter than August, and should give days 3 more.

Confirmed in FF 2.0.0.6 :-/ But where is the error here? If it isn't mine,
can someone quickly point out anything in ES3 that specifies it?

> var
a = formField.value.split("/"),
d = new Date(
parseInt(a[2], 10), parseInt(a[1], 10), parseInt(a[0], 10) + 50);

d = new Date(a[2], a[1]-1, a[0]+50) // suffices

Would that not have the same February problem as my solution?

One can replace, in this context, parseInt by unary +; and that will in
context be effectively implicit.

I had thought about that, but what about octals?

> anotherFormField.value =
String(d.getDate() * 1e6 + d.getMonth() * 1e4 + d.getFullYear())
.replace(/(\d\d)(\d\d)(\d{4})/, "$1/$2/$3");

Do you find that better than, with suitable LZ,

anotherFormField.value =
LZ(d.getDate()) + '/' + LZ(d.getMonth()+1) + '/' + d.getFullYear()

// ??

Hm. No. I just liked your previous solution and had my quickhack based on it.
PointedEars
--
"Use any version of Microsoft Frontpage to create your site. (This won't
prevent people from viewing your source, but no one will want to steal it.)"
-- from <http://www.vortex-webdesign.com/help/hidesource.htm>

[Randy Webb]

Thomas 'PointedEars' Lahn said the following on 8/8/2007 6:18 PM:

ginajohnst wrote:

>On Aug 8, 9:48 pm, Lee <[e-mail]:

>>ginajohnst said:
Once you understand it completely, you should be able to come up
with a much simpler solution that actually works.

My solution works alright.

Is that why you agreed with John when he pointed out a flaw in it?

If one had tested it, as I did, one would have known.

Obviously you didn't or you wouldn't have agreed with John in his
assessment of it having flaws in it.

But what to expect from a noname person with headers disregarding
Internet standards, Netiquette and their ISP's terms of service?

Whatever you were smoking, snorting or swallowing when you wrote that
garbage you should endeavor to stay away from.

--
Randy
Chance Favors The Prepared Mind
comp.lang.javascript FAQ - http://jibbering.com/faq/index.html
Javascript Best Practices - http://www.JavascriptToolbox.com/bestpractices/

[Lee]

Thomas 'PointedEars' Lahn said:

>
ginajohnst wrote:

>On Aug 8, 9:48 pm, Lee <[e-mail]:

>>ginajohnst said:

>>Once you understand it completely, you should be able to come up
with a much simpler solution that actually works.

My solution works alright. If one had tested it, as I did, one would have
known. But what to expect from a noname person with headers disregarding
Internet standards, Netiquette and their ISP's terms of service?

You think you tested that?

Can you explain how it can work properly when you don't subtract
one from the month before passing it to the Date constructor?

Can you explain how your ludicrous multiplication method works
if the resulting date is earlier than the 10th of the month?

Try these inputs, genius:
01/11/2008
13/11/2008
--

[Dr J R Stockton]

In comp.lang.javascript message <Xn********************@194.109.133.242>
, Wed, 8 Aug 2007 21:32:37, Evertjan. <ex**************@interxnl.net>
posted:

>

>d = new Date(d.getTime() + 50*24*60*60*1000);

safer:
d.setTime(d.getTime() + 50*24*60*60*1000);

Better, yes; but why safer?

>or, also easier:
d.setDate(d.getDate() + 50);

That's also safer. Starting at Saturday 2007-03-24 23:30, the first
gives us a Monday and the second a Sunday. 50 days are 7 weeks plus ONE
day.

Re another article : parseInt(S) for S being "08" or "09" gives zero
(the standard reluctantly allows that); so, in this context, if parseInt
is used then it does need ', 10'.

But without parseInt, "08" and "09" are taken as eight and nine;
although "077" is sixty-three, "078" is seventy-eight - at least,
wherever I've tried it. That seems compatible with ISO/IEC 16262 B.1.

Javascript lacks specific syntax for creating a Date Object of a given
Ordinal Date; it does not need any, since new Date(YYYY, 0, DDD)
suffices. For DDD, parseInt(DDD, 10) seems essential.

new Date(2007, 0, 077) // Mar 4
new Date(2007, 0, 078) // Mar 19

Similar considerations apply to YYYY - parseInt is necessary unless most
years before 800 will definitely not be used.

--
(c) John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v6.05 IE 6.
Web <URL:http://www.merlyn.demon.co.uk/- w. FAQish topics, links, acronyms
PAS EXE etc : <URL:http://www.merlyn.demon.co.uk/programs/- see 00index.htm
Dates - miscdate.htm moredate.htm js-dates.htm pas-time.htm critdate.htm etc.

[Evertjan.]

Dr J R Stockton wrote on 09 aug 2007 in comp.lang.javascript:

In comp.lang.javascript message <Xn********************@194.109.133.242>
, Wed, 8 Aug 2007 21:32:37, Evertjan. <ex**************@interxnl.net>
posted:

>>

>>d = new Date(d.getTime() + 50*24*60*60*1000);

safer:
d.setTime(d.getTime() + 50*24*60*60*1000);

Better, yes; but why safer?

Because this

d = new Date((a[2]), (a[1])-1, (a[0]));
d = new Date(d.getTime() + 50*24*60*60*1000);

is less understandable, so is bound to have more mistakes made.

>>or, also easier:
d.setDate(d.getDate() + 50);

Pentakosta [Gr., 50] gives a perfect Pesach to Shavuot+1 arythmatic.

That's also safer. Starting at Saturday 2007-03-24 23:30, the first
gives us a Monday and the second a Sunday. 50 days are 7 weeks plus ONE
day.

Yes, indeed!
--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

[Lee]

Dr J R Stockton said:

>
In comp.lang.javascript message <f9*********@drn.newsguy.com>, Wed, 8
Aug 2007 05:48:47, Lee <RE**************@cox.netposted:

>>My date is in the string format dd/mm/yyyy eg. 23/08/2007 in my

>>Once you understand it completely, you should be able to come up
with a much simpler solution that actually works.

http://docs.sun.com/source/816-6408-10/date.htm

/* There must be a nicer-looking version of that page, with a margin */
/* Note its error in a line starting like <tt>milliseconds</tt*/
/* They seem to ignore that UT != UTC */

Which parts of that page d0 you believe to deal with the reading and
writing of non-FFF numeric date strings??

The information about the constructor and the various setters
and getters seemed useful. The question involved more than
simply reading and writing date strings.
--

[Dr J R Stockton]

In comp.lang.javascript message <f9*********@drn.newsguy.com>, Wed, 8
Aug 2007 16:40:17, Lee <RE**************@cox.netposted:

>Thomas 'PointedEars' Lahn said:

>...

Can you explain how your ludicrous multiplication method works
if the resulting date is earlier than the 10th of the month?

The multiplication method is currently good for generating YYYYMMDD.

It is not good for DDMMYYYY or 8-digit FFF.

OTOH, given that separators are required, consider

d = new Date("1234/01/02") // 1234 Jan 2
X =
String(d.getFullYear()*1e4 + d.getMonth()*1e2 + d.getDate() + 100)
.replace(/(\d{4})(\d\d)(\d\d)/, "$3/$2/$1");

Change the \d{4} to \d+ and the code will be shorter and last longer.

--
(c) John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v6.05 IE 6.
Web <URL:http://www.merlyn.demon.co.uk/- w. FAQish topics, links, acronyms
PAS EXE etc : <URL:http://www.merlyn.demon.co.uk/programs/- see 00index.htm
Dates - miscdate.htm moredate.htm js-dates.htm pas-time.htm critdate.htm etc.

[Dr J R Stockton]

In comp.lang.javascript message <fZ**************@invalid.uk.co.demon.me
rlyn.invalid>, Fri, 10 Aug 2007 21:04:47, Dr J R Stockton
<jr*@merlyn.demon.co.ukposted:

>In comp.lang.javascript message <46**************@PointedEars.de>, Fri,
10 Aug 2007 09:27:13, Thomas 'PointedEars' Lahn <Po*********@web.de>
posted:

>>Dr J R Stockton wrote:

>>Javascript lacks specific syntax for creating a Date Object of a given
Ordinal Date;

Define "Ordinal Date". If you mean something like the number of
milliseconds since the beginning of the UNIX era, then

It is defined in ISO 8601, which is IIRC released as an EN and possibly
a DIN. Alas, 8601 is AFAIK not free (unlike 8602); but the definition
is easily found by Google.

Correction : I had forgotten that ISO 8601:2004 was in fact available
free in PDF, from ISO, <http://isotc.iso.org/livelink/livelink?func=ll&o
bjId=4020763&objAction=browse&sort=nameprobably; and from OMG -- links
are on my site, but I forget which I actually used. It seems that ISO
do allow one to pay for the paper version and for the PDF, if one so
wishes.

--
(c) John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v6.05 IE 6.
Web <URL:http://www.merlyn.demon.co.uk/- w. FAQish topics, links, acronyms
PAS EXE etc : <URL:http://www.merlyn.demon.co.uk/programs/- see 00index.htm
Dates - miscdate.htm moredate.htm js-dates.htm pas-time.htm critdate.htm etc.

[dhtmlkitchen]

On Aug 8, 12:16 am, ginajohnst <[e-mail]:

Hi All.

I'm having a problem adding days to a date.

My date is in the string format dd/mm/yyyy eg. 23/08/2007 in my
form field.

I can't work out how to add 50 days to that date and then write it to
another form field.

I'll try a more explicit approach.

The first step is to add 50 days to the date object.

// get the date.
var date = new Date();
var dayOfMonth = date.getDate()); // This API method "getDate" should
be renamed to "getDayOfMonth".

// add 50 days.
date.setDate( dayOfMonth + 50 );

Any help would be appreciated.

Write a unit test to verify each step.

Here is a horrible ad hoc test:
javascript:alert(new Date (new Date().setDate( new Date().getDate() +
50 ) - ( 50 * 24 * 60 * 60 * 1000 ) ) )

Garrett

[dhtmlkitchen]

The problem appears that there is no standard way of formatting a Date
to a customized string.

It seems possible to format a Date string using a RegExp, but the Date
string cannot be guaranteed to be in a specific format.

I would like to see this added to ES4.

var s = "EEE, MMM d, yyyy"
var df = DateFormat( s );
var formattedDay df.format( new Date() ); // Thu, Aug 23, 2007.

http://java.sun.com/j2se/1.5.0/docs/...ateFormat.html

[Thomas 'PointedEars' Lahn]

dh**********@gmail.com wrote:

[...]
date.setDate( dayOfMonth + 50 );

You are a *little* late. <Xn********************@194.109.133.242>
PointedEars
--
var bugRiddenCrashPronePieceOfJunk = (
navigator.userAgent.indexOf('MSIE 5') != -1
&& navigator.userAgent.indexOf('Mac') != -1
) // Plone, register_function.js:16

[Dr J R Stockton]

In comp.lang.javascript message <11*********************@z24g2000prh.goo
glegroups.com>, Thu, 23 Aug 2007 23:48:11, "dh**********@gmail.com"
<dh**********@gmail.composted:

>The problem appears that there is no standard way of formatting a Date
to a customized string.

It seems possible to format a Date string using a RegExp, but the Date
string cannot be guaranteed to be in a specific format.

I would like to see this added to ES4.

var s = "EEE, MMM d, yyyy"
var df = DateFormat( s );
var formattedDay df.format( new Date() ); // Thu, Aug 23, 2007.

http://java.sun.com/j2se/1.5.0/docs/...ateFormat.html

Since that is Java, and this is a Javascript newsgroup, ISTM that you
have a severe sagacity deficiency.
It's a good idea to read the newsgroup c.l.j and its FAQ. See below.

--
(c) John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v6.05 IE 6
news:comp.lang.javascript FAQ <URL:http://www.jibbering.com/faq/index.html>.
<URL:http://www.merlyn.demon.co.uk/js-index.htmjscr maths, dates, sources.
<URL:http://www.merlyn.demon.co.uk/TP/BP/Delphi/jscr/&c, FAQ items, links.

[Dr J R Stockton]

In comp.lang.javascript message <11*********************@r23g2000prd.goo
glegroups.com>, Thu, 23 Aug 2007 23:43:35, "dh**********@gmail.com"
<dh**********@gmail.composted:

>Here is a horrible ad hoc test:
javascript:alert(new Date (new Date().setDate( new Date().getDate() +
50 ) - ( 50 * 24 * 60 * 60 * 1000 ) ) )

That will, at present, show the present date and time.

But change both instances of 50 to 130, and it will probably show you an
hour after present time, but might show the present time or an hour (or
half an hour, but that's unlikely) before present time.

Until you understand that, it would be better if you did not try to
answer Javascript date questions.

--
(c) John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v6.05 IE 6.
Web <URL:http://www.merlyn.demon.co.uk/- w. FAQish topics, links, acronyms
PAS EXE etc : <URL:http://www.merlyn.demon.co.uk/programs/- see 00index.htm
Dates - miscdate.htm moredate.htm js-dates.htm pas-time.htm critdate.htm etc.

[Randy Webb]

Dr J R Stockton said the following on 8/24/2007 4:24 PM:

In comp.lang.javascript message <11*********************@z24g2000prh.goo
glegroups.com>, Thu, 23 Aug 2007 23:48:11, "dh**********@gmail.com"
<dh**********@gmail.composted:

>The problem appears that there is no standard way of formatting a Date
to a customized string.

It seems possible to format a Date string using a RegExp, but the Date
string cannot be guaranteed to be in a specific format.

I would like to see this added to ES4.

var s = "EEE, MMM d, yyyy"
var df = DateFormat( s );
var formattedDay df.format( new Date() ); // Thu, Aug 23, 2007.

http://java.sun.com/j2se/1.5.0/docs/...ateFormat.html

Since that is Java, and this is a Javascript newsgroup, ISTM that you
have a severe sagacity deficiency.

If you had bothered to read, and comprehend, the line preceding the code
posted you would have realized some things that you are either too
arrogant or too ignorant to admit, possibly - and probably - both.

--
Randy
Chance Favors The Prepared Mind
comp.lang.javascript FAQ - http://jibbering.com/faq/index.html
Javascript Best Practices - http://www.JavascriptToolbox.com/bestpractices/